blob: 110a8fe5f7d0f7b89f98097183ebc66ee65395de (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date: 15. February 2012
* $Revision: V1.1.0
*
* Project: CMSIS DSP Library
* Title: arm_max_q7.c
*
* Description: Maximum value of a Q7 vector.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
* Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
* Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
* Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
* Documentation updated.
*
* Version 1.0.1 2010/10/05
* Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
* Production release and review comments incorporated.
* ---------------------------------------------------------------------------- */
#include "arm_math.h"
/**
* @ingroup groupStats
*/
/**
* @addtogroup Max
* @{
*/
/**
* @brief Maximum value of a Q7 vector.
* @param[in] *pSrc points to the input vector
* @param[in] blockSize length of the input vector
* @param[out] *pResult maximum value returned here
* @param[out] *pIndex index of maximum value returned here
* @return none.
*/
void arm_max_q7(
q7_t * pSrc,
uint32_t blockSize,
q7_t * pResult,
uint32_t * pIndex)
{
#ifndef ARM_MATH_CM0
/* Run the below code for Cortex-M4 and Cortex-M3 */
q7_t maxVal1, maxVal2, out; /* Temporary variables to store the output value. */
uint32_t blkCnt, outIndex, count; /* loop counter */
/* Initialise the count value. */
count = 0u;
/* Initialise the index value to zero. */
outIndex = 0u;
/* Load first input value that act as reference value for comparision */
out = *pSrc++;
/* Loop unrolling */
blkCnt = (blockSize - 1u) >> 2u;
/* Run the below code for Cortex-M4 and Cortex-M3 */
while(blkCnt > 0u)
{
/* Initialize maxVal to the next consecutive values one by one */
maxVal1 = *pSrc++;
maxVal2 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and its index */
out = maxVal1;
outIndex = count + 1u;
}
maxVal1 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal2)
{
/* Update the maximum value and its index */
out = maxVal2;
outIndex = count + 2u;
}
maxVal2 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and its index */
out = maxVal1;
outIndex = count + 3u;
}
/* compare for the maximum value */
if(out < maxVal2)
{
/* Update the maximum value and its index */
out = maxVal2;
outIndex = count + 4u;
}
count += 4u;
/* Decrement the loop counter */
blkCnt--;
}
/* if (blockSize - 1u) is not multiple of 4 */
blkCnt = (blockSize - 1u) % 4u;
#else
/* Run the below code for Cortex-M0 */
q7_t maxVal1, out; /* Temporary variables to store the output value. */
uint32_t blkCnt, outIndex; /* loop counter */
/* Initialise the index value to zero. */
outIndex = 0u;
/* Load first input value that act as reference value for comparision */
out = *pSrc++;
blkCnt = (blockSize - 1u);
#endif /* #ifndef ARM_MATH_CM0 */
while(blkCnt > 0u)
{
/* Initialize maxVal to the next consecutive values one by one */
maxVal1 = *pSrc++;
/* compare for the maximum value */
if(out < maxVal1)
{
/* Update the maximum value and it's index */
out = maxVal1;
outIndex = blockSize - blkCnt;
}
/* Decrement the loop counter */
blkCnt--;
}
/* Store the maximum value and its index into destination pointers */
*pResult = out;
*pIndex = outIndex;
}
/**
* @} end of Max group
*/
|
